Need advice. New (to me) 911 smokes.

[LuvNH]

Hello all. Thanks in advance.

New owner of a 79 SC.

PO swapped the original engine for a 78 engine (determined by s/n near fan and vin). I have the original engine (again, I assume based on that s/n) which was likely used for parts.

I knew that it smoked when I got it, and had a local shop (Porsche savvy) look at it. They ran it, degreased, added oil and a dye pack ran it to check for leaks. I was told that it was difficult to pinpoint the location of leak bc it was coming from everywhere. Got a quote for $5400 to drop engine and fix the typical 3 locales on the top. That’s an expensive (and far from complete) guess, so I got the car back to explore more options.

During my own cleaning, there was oil behind the air filter which I have learned comes from overfilling the oil. Dipstick was dry. Engine was cold - I get it.

The engine starts right up, but absolutely belches smoke. Creates a smokescreen and smokes up the interior after a few minutes. Revving the engine causes oil to spit out of the exhaust pipe. I heard lots of dripping sounds after I turned off engine. Dipstick was wet after a few minutes, not fully. Although the engine ran only for a few minutes.

Engine sounds fine, and moved the car forward and back a bit. Clutch feels fine.

After two weeks of sitting, it has dripped from three places. Mostly from the exhaust pipe, and there is a small puddle sitting on the lip there now. Also from the right side flange where the muffler meets the heat exchanger. I’m surprised the puddles are not larger. On cardboard only a couple inches across at best.

One shop said they could look into it and do any necessary work up only up to the cylinders. They won’t take them off and go further. No real price quote here.

Another shop recommends a reseal, all the way to splitting the case. Said they would take it apart, inspect and measure everything and replace as necessary. Not sure how this differs from a rebuild. Quoted price was $30K-$40K.

Need some advice.

[David Inc.]

Drain the oil completely from both the engine and sump, put in 10 quarts, and try again. If it's overfilled you can't figure anything else out until it's not overfilled. Once you know that the engine isn't overfull and can run safely you can let it run and warm up.

[dg567]

How long has it been sitting? It's not uncommon for the oil to settle into the muffler after sitting for long periods of time.

But I agree, drain all the oil and I would add 7 quarts, and bring up to temp and add oil slowly until you start to see it on the dipstick.

Clean everything and inspect for fresh leaks.

[Winter]

Just know that once you have a baseline - correct - oil level, that any residual oil from an overfill can still present itself as leaks, dripping off the engine from a variety of places when the engine warms up until it has fully burned off.

Good advice above. Get the baseline level correct (even experienced shops can overfill, ask me how I know), go from there. Oil leaks from valve covers, oil return tubes and other spots are relatively easy DIY fixes.

[LuvNH]

Thanks for the quick responses!

This makes sense and I’ll likely start there, but would the smoke be so immediate and consistent if overfilling is the problem?

And it has sat. Ran three times for very short durations (5 min max) each time in the past year at a minimum.

[Winter]

There could be a variety of issues, smoke is probably from the sitting. I have not personally resurrected a 911 from a long slumber, but there are a fair amount of threads here talking about lots of smoke in the initial “getting it running” + “start up” stages, and then the “Italian tune up” method to resolve it.

I think the first step is making sure you are not running too much oil and then moving onto addressing leaks and burning off oil in the exhaust (Italian tune up) via driving it. Probably worth doing a search here and reading a few threads on this subject. Good luck.

[$yncro]

Most common oil leaks that's hard to see would be, oil pressure switch, oil breather cover gasket, thermostat o ring that's from the top of the engine. From the bottom check your oil cooler they tend to leak as well. These are minor job for DIY imo just time consuming. Maybe post pics of your engine and where you think it's leaking.

[kd126500]

What was mentioned above. Ask me how I know. Sounds like at some point too much oil was added and backed up through the system. I had this happen and ended up removing my headers and flushing the extra oil out as it was taking so long to burn off. Drain the oil, fill to the lower limit, clean the engine of old reside and drive the car long enough for the oil to burn off and out of the exhaust. If you still have an issue at this point, you should see leaking somewhere.

[EC900]

Gaskets and O-Rings all over could be dry rotted etc.
Triangle Of Death (TOD) is where you need to focus search topics, get a cheap borescope to search the hard to access areas.

If you’re or were in an overfill situation, or leaks are real bad…for now as you start engine to figure out more…you may want to remove the hoses from your heat exchangers into the cabin until the oil residue has burned off. You don’t want oily air lingering, though creates not only the distinction of air cooled but can tarnish up contacts and gauges.

Start-up smoke from worn valve guides will last about 5 minutes or less as it burns off whatever amount pooled in the cylinder(s) typical when they sit for months. Less noticeable if driven more frequently.
Brake cleaner, good flashlight and constant monitoring. If you can pinpoint for a mech all the better saves $$.
Another leak prone area are rear chain covers and crank seal could be leaking, easy enough done with engine in, new valve covers/gaskets and valve adjustment while you’re at it.
Replacing valve cover gaskets is routine but be sure the covers are not warped. Same for oil return tubes (originals are single whereas replacements are 2-part for ease of install, and also check crimped oil hoses, old rubber fails there.

$30-40k is a totally rebuilt engine by a master shop.
Sure cases leak, just a re-torque bolts could solve issues before doing a top end a lot cheaper by half.

[911obgyn]

At least it runs! I bought an 85 911 sat for over a year bug puddle under the engine, moldy interior, charged the battery did a cold compression test. Bought it for all the money i had at the time. Drove it home in a cloud of smoke about 15 miles. Spent average about 300$ a month for a year doing oil leaks deferred maintinence and cleaning it up. Has been running great for 15 years since. Did all the work myself with the help of this community. Good luck on your journey. Stopped smoking heavy after the first 50 miles. Probably yours has lots of oil in heat exchangers which will take getting it hot and flogging i, as above do oil change, valve adjust, gaskets return tubes drive and assess!

[dannobee]

Probably has a TON of oil in the exhaust and muffler. It'll take awhile to burn it all out. One way to do it without pulling off the bumper, muffler, and the rest of the exhaust is to verify the oil level, then blast it down the freeway. At night works best when there is less traffic and the smoke is less noticeable. If you're just idling it at home the exhaust will never get hot enough to burn it all out.

[snbush67]

It is amazing how much oil will come out of a lower valve cover with a bad gasket or loose nuts. And any oil coming out of the valve covers is dripping right on your heat exchangers. That should be your first step, remove the cover's replace the gaskets, check all head studs and adjust the valves.

Eventually you’re going to have to pull the exhaust and clean it out, the caked on oil in the heat exchangers will continue to smoke and you’ll get smoked every time you try to use the heat.

[brighton911]

LuvNH That quote to correct the topside oil leaks is ridiculous. It can be done with the engine in place and I'm hoping you will give it a try. 911's are not all that complicated and the resources of this site are almost endless. And as others have said, the exhaust system is full of oil so a a spirited drive (not in the city) will go a long way in clearing it up. Then you can determine if there is actual oil consumption by the engine. Good luck

[rowingone]

I had a similar problem with my 72 that had been sitting a long time before I purchased it. I removed the muffler and tipped it up and half a quart of oil came out . . so I would get the correct amount of oil in there as suggested and remove the muffler and drain it and then run it up to temp to burn off residual then take next steps. If the smoke is coming out your exhaust then start there before you tackle other leaks.

[ant7]

Originally Posted by rowingone

I had a similar problem with my 72 that had been sitting a long time before I purchased it. I removed the muffler and tipped it up and half a quart of oil came out . . so I would get the correct amount of oil in there as suggested and remove the muffler and drain it and then run it up to temp to burn off residual then take next steps. If the smoke is coming out your exhaust then start there before you tackle other leaks.

[Bill Douglas]

As mentioned above a few times, drain the oil out of the sump plug and the tank, put ten quarts in the tank etc. Then take it for a discrete drive for half an hour and burn all that oil out of the cylinders and exhaust. With a bit of luck the engine may be fairly much OK and just need a burn off.

[LuvNH]

This is excellent!! It gives me hope that this MAY not be too far gone. It is pleasantly surprising that so many opinions align with respect to overfill.

I’ll first drain and refill oil - 9 qts to start.

I will remove the hose that connects the air to the cabin. Now I know why it was missing in the first place!

***correction*** The quote was for $4500, and was to replace valve cover gaskets and the TOD.

This engine has the upgraded turbo valve covers and hydraulic chain tensioners. The bracket that holds is upgraded too. Also has a different sump plate, not the stock one.

Before I personally ran it, I used my rifle boroscope to look around and honestly it looked surprisingly dry. You could see oil on the top of the valve covers near the fan shroud though. I’ll check again.

I’ll look at hoses and all connections too.

I fear that there is a ton of oil in the exhaust as you all suggest. Removing the muffler crossed my mind but seeing the bolts made me wary. Now that you say that there could be that much oil in there is making me reconsider.

It will be a little while, but I’ll report back.

Once again, many thanks!!

[porsche930dude]

Yup I think its not a big deal. Definately sounds like it got overfilled and oil went everywhere that it shouldnt be. Atleast not to jump into any repairs yet. The oil level should only be checked hot at idle on a level surface. Plus they tend to smoke after sitting for any length of time. I wouldnt pull anything apart. Just run it and burn it off it will take a while.

[brighton911]

LuvNH, be sure to include an update, it's always nice to know the outcome of a problem.

[shoooo32]

Most shops are not interested in chasing engine leaks. It's all or nothing (engine out service) and the pricing you were quoted reflects that.

Post some photos. This group has seen it all and can probably walk you through your options a little better with detailed photos to review.